Tài liệu User Defined Primitives part 1 pdf

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12.1 UDP basics

In this section, we describe parts of a UDP definition and rules for UDPs.

12.1.1 Parts of UDP Definition

Figure 12-1 shows the distinct parts of a basic UDP definition in pseudo syntax form. For

details, see the formal syntax definition described in Appendix , Formal Syntax

Definition.

Figure 12-1 Parts of UDP Definition

//UDP name and terminal list

primitive <udp_name> (

<output_terminal_name>(only one allowed)

<input_terminal_names> );

//Terminal declarations

output <output_terminal_name>;

input <input_terminal_names>;

reg <output_terminal_name>;(optional; only for sequential

UDP)

// UDP initialization (optional; only for sequential UDP

initial <output_terminal_name> = <value>;

//UDP state table

table

<table entries>

endtable

//End of UDP definition

endprimitive

A UDP definition starts with the keyword primitive. The primitive name, output terminal,

and input terminals are specified. Terminals are declared as output or input in the

terminal declarations section. For a sequential UDP, the output terminal is declared as a